Can a cat's heart murmur cause difficulty breathing or gasping?

Hello and thank you for reaching out to Petco Pet Education Center, formerly Petcoach. When cats pant or breathe with their mouths open, this is abnormal and concerning. Given the information you provided about the Merlin's heart murmur, I am worries that he could have significant enough heart disease to cause heart failure, which leads to the build up of fluid in the lungs. This makes it very difficult for cats to breathe, especially after exertion, and can be life-threatening. Alternatively, cats can pant when they are severely overheated, which is also very dangerous. I would recommend keeping Merlin quiet (no running or playing) until he can be seen by a veterinarian. He/she will want to do a full physical exam and take x-rays of Merlin's chest to look for heart enlargement and/or fluid in the lungs. There is a blood test available called an NT-proBNP that can detect heart failure in cats as well. I hope this information is helpful!

With any cat showing potential signs of respiratory distress this is an immediate emergency. I strongly recommend going to the ER clinic now. I cardiac disease in cats often goes undetected until the point that they have difficulty breathing. Hopefully it's not that serious but it is worth erring on the side of caution and getting her checked as soon as possible. Best of luck to Maud and thank you for using Petco Pet Education Center, formerly Petcoach

I understand that, but Mimu is having trouble breathing so it's a medical emergency. This will be very distressing to him, and it may be he is having heart problems such as heart failure. Heart failure will cause fluid to build up back in his lungs, causing labored breathing. If he does have this and it's left untreated, he will literally drown in fluid in his lungs. You do not want to do that to him, so you need to bring him into a vet immediately. If he does have heart failure, there are medications that can be prescribed to make him more comfortable and diminish his symptoms. Please take him into a vet now. Best of luck.

This is not normal behavior. I would be worried that Mister has an abnormality in his heart or his lungs that could eventually become life threatening. I would recommend to have him examined by his vet. Depending on the physical exam findings, there are a number of things that may be needed as the next steps to diagnose his condition and to provide the appropriate treatment. I hope this helps!

Increased respiratory rate can be a sign of congestive heart failure and it sounds like you should have your vet examine Wriggy soon. Thyroid disease is also common in older cats and can cause an increased heart rate and ravenous appetite typically along with weight loss.

I am so sorry that your kitty died. The fact that he had a heart murmur means that he likely died of a blood clot in the lungs which then actually killed him. There would have been no way to save him and you would not have been able to prevent it. It is just one of those terrible things that happen. But he had 5 great years with you and that is something you can be proud of.

Asthma is the # 1 cause for these symptoms. However, it could also be pain from the lower GI tract, underlying heart disease, pleural effusion, or any other lung disorder. If this continues for more than 3-6 hrs, or if Harley seems to have labored breathing and isn't oxygenating well (blue tongue, open mouth breathing, etc), then its best to take him in to your vet for bloodwork +/- chest x-rays to help diagnose the underlying problem and get him on the proper treatment. I hope that Harley feels better soon! Best wishes and take care.